I want to +1 this too!  I use a Stream Deck and have my input controls mapped to buttons on it.  I'd love to toggle 50/50 PBP with fulls screen!

Here's a workaround I just tested with my P3421W.

Title: [Guide] How to Toggle PBP/PIP on Dell Monitors with a Keyboard Shortcut (Bypassing DDPM)

If you've been frustrated trying to set up a hotkey to toggle Picture-by-Picture (PBP) on Dell monitors (like the P3421W) because the new Dell Display and Peripheral Manager (DDPM) lacks the option or the command line interface is buggy, here is a rock-solid workaround.

Instead of fighting Dell's software, you can completely bypass it and send raw DDC/CI hardware commands directly to your monitor over your display cable using a free, lightweight tool.

Here is how to set it up:

Prerequisites

Download ControlMyMonitor from NirSoft. It is a free, portable executable, so there is no installation required. Extract it to a permanent folder on your PC.

Step 1: Find Your Monitor's PBP Codes

First, we need to find the exact raw values your specific monitor uses for "Off" and "On".

1. Open ControlMyMonitor.exe. You will see a table listing all the hardware settings your monitor supports.

2. Look at the VCP Code column. Dell typically uses E9 to control PIP/PBP Mode.

3. Use your monitor's physical joystick to turn PBP ON.

4. Go back to the app, press F5 to refresh the table, and note the "Current Value" for E9.

5. Turn PBP OFF with the physical joystick, press F5 again, and note the new value.

(Note: For many Dell monitors, 0 is Off, and 2 or 36 is PBP mode. Keep your two numbers handy).

Step 2: Create the Toggle Shortcut

ControlMyMonitor has a brilliant built-in CLI command specifically for toggling between two states, which means we don't even need to write a script.

1. Right-click your Windows Desktop > New > Shortcut.

2. In the target box, point it to your executable, followed by the /SwitchValue argument, your monitor target (Primary), the VCP code (E9), and your Off/On values.

It should look exactly like this:

"C:\Path\To\ControlMyMonitor.exe" /SwitchValue Primary E9 0 2

(Make sure to update the path to wherever you saved the .exe, and replace 0 and 2 with the specific values you found in Step 1).

3. Click Next, name the shortcut "Toggle PBP", and click Finish.

Step 3: Assign Your Hotkey

Now we just need to bind that shortcut to your keyboard.

1. Right-click your new "Toggle PBP" shortcut and select Properties.

2. Click into the Shortcut key box.

3. Press your desired key combination (e.g., Ctrl + Alt + P) and hit Apply.

That’s it! Pressing that hotkey will now instantly toggle your monitor into PBP mode, and pressing it again will toggle it back to fullscreen.

Bonus Tip: If you ever want to write a script to automate which input is displayed in the second PBP window (HDMI vs. DisplayPort vs. USB-C), look at VCP code E8 in ControlMyMonitor. That code controls the Secondary Input Source.

"C:\Program Files\controlmymonitor\ControlMyMonitor.exe" /SwitchValue Primary E9 0 36

Thanks for the tips. @eddaygeee I made a pbp-normal toggle batch file, which configures the main (60) and sub (E8) inputs and layout mode.  Instead of using SwitchValue, the script use GetValue from E9 to determine current layout mode (0 or 36).  Then it goes to corresponding SetValue command sequence.  I use AutoHotKey to run it by an assigned hotkey.  I finally uninstalled DDM (DDMP never worked for this purpose).

well where's your code? :)

On github, search toggle-pbp-dell-monitor  :)

Are you referring to the end of life and support DDM (Dell Display Manager) or the new DDPM (Dell Display and Peripheral Manager)?

@shanekm . The feature you are asking for is available in latest DDPM v2.1.0.24.

@DELL-Chris M​ 

No, what I’m saying is that it would be great to have the ability to create a hotkey that switches from a favorite input (e.g., DP) to a split-screen 50/50 PBP mode (using two sources, e.g., DP and Thunderbolt), and another hotkey to switch back to full screen/fav source (e.g., DP).

Ex: Hotkey press -> goes from DP (full screen) to 50/50 PBP (DB and Thunderbolt). 

Press another Hotkey to go back to full screen (ex DP) 

@karthikv912​ pls see above

The one you're referring to is ability to swap inputs only AFTER you're already in PBP

Hello @shanekm ,

To clarify, are you specifically looking for an enhancement that allows you to:

• Use one hotkey to switch from your favorite full-screen input (Example: DP) to a PBP 50/50 split view (Example: DP + Thunderbolt), and

• Use another hotkey to return back to that full-screen input again?

Is this the correct understanding. ? Please let know